Method for making valve tappets



Dec. 14, 1937. A. s PLATER 2,101,917

METHOD FOR MAKING -VALVE TAPPETS Filed Jan. 25, 1935 ATTORNEY.

Patented Dec. 14, 1937 UNITED STATES PATENT OFFlCE 2,101,917 7 METHOD FOR MAKING VALVE TAPPETS Albert splitter, Saginaw, Mich. Application January 25,1935, Serial No. 3,456

4 Claims. (o1. 23456.7)

This invention relates to a method of making a valve tappet, and it is the prime object of the invention to provide a tappet which can be readily and economically manufactured, which is of minimum weight, and which has the necessary characteristics to insure a maximum life of bearing surfaces in an economical and eificient manner.

Another object of the invention is to provide a method of making a tappet structure in which the various parts are rigidly united in one rugged and solid structure, and which requires no machine work other than grinding to finish.

Another object is to provide a rugged tappet which readily withstands the sharp impacts to which tappets are subjected when used in internal combustion engines, and which is provided with means for deadening noise occasioned by the mechanical operation of the tappet.

A further object is to provide a method of manufacture which is simple, practical, and economical, which requires a minimum of finish or machine work, and which provides a rigid onepiece unitary structure when assembled.

The above and other objects will appear as the specification progresses, reference being had to the accompanying drawing in which I have shown the preferred embodiment of my invention, and in which like reference numerals indicate like parts throughout the several views thereof.

In the drawing- Fig. 1 is a side view of my improved valve tappet.

Fig. 2 is a central sectional longitudinal view through the tappet.

Fig. 3 is a top plan view.

Fig. 4 is a sectional view illustrating the casting of the head with the core inserted.

Fig. 5 is a side view of the core.

Fig. 6 is a plan view thereof.

Fig. 7 is an opposite end View.

Fig. 8 is a fragmentary part sectional view similar to Fig. 2, showing the one end of the stem formed similar to the core.

Fig. 9 is a fragmentary view of the stem before the head has been cast thereon.

Referring now more specifically to Figs. 1 to 7 of the drawing, the numeral Ill indicates a core member preferably cylindrical in shape and formed with a centrally disposed opening I l as shown. This is preferably formed from stock of uniform size and is turned to various diameters, the reduced section l2 terminating in an enlarged upper rim or flange I3, in which a plurality of spaced apart slots [4 are formed, these slots extending through the rim and section I 2 down to the section I5 which is of larger diameter than the section [2, the lower end N5 of the core being of approximately the same diameter as the upper rim or flange.

These cores are formed on automatic machines and are in turn cast in the head of the tappet, a preferably copper disc I! being pressed in the neck of the core, said disc limiting the flow of metal and deadens noise when the tappet is operating in an engine. In forming the head, the core Ill is first placed in a suitable flask l8 which is usually of disc shaped form, the moulten metal which forms the head being indicated at Hi. This moulten metal is poured into the flask, filling the slots and centrally disposed openingup to the copper disc l1, and when the metal cools, the core will be firmly anchored and embedded, forming a rigid unitary structure which requires no machining other than finish grinding.

In the construction shown in Figs. 1 to 7 inclusive the projecting end It of the core forms a neck, the face 20 of which provides a smooth surface to which the end of a stem member 2| is welded, and this stem can be solid, or can be hollow as shown in the drawing hereunto annexed, the opposite end of the stem being shouldered as at 22 and is internally threaded as at 23 to receive the usual adjustment screw (not shown).

In Figs. 8 and 9 of the drawing I have shown the end ofthe stem turned to substantially the same shape as the core l0, and this is treated in exactly the same manner, the disc I! being inserted in the neck, after which the turned end of the stem is placed in the flask and the head I9 cast thereon. Such construction eliminates any welding operation, and thereby materially lessens the cost of manufacture.

It will, of course, be obvious that the core proper may be in the form of a stamping if desired and that the head l9 can be cast thereon, after which it is welded to the stem in the usual manner.

This method and construction has many advantages over the conventional tappets in general use, inasmuch as the entire head can be uniformly chilled due to the fact that no machining is necessary after the head is cast in position. It provides a substantial unitary structure, the neck of which is rigid and strong, and. the entire tap pet requires no machining other than finish grinding, making it very economical to manufacture.

From the foregoing description it will be obvious that I have perfected a very simple, practical, and inexpensive tappet and method of producing it.

What I claim is:

1. The method of forming a 'tappet which includes providing a hollow core, placing said core in a flask and casting a head upon one end portion thereof, so as to leave a hollow portion of the core exposed beyond the head, and then welding a stem to said hollow exposed end of the core.

2. The method of forming a tappet which includes forming a tubular core, inserting a sound deadening disc in the core at a point intermediate the ends thereof to divide the same into hollow end portions, placing the core in a flask and casting a head upon one end thereof so that the material of the head extends in the hollow to said disc, and then welding a stem to the other exposed hollow end of the core.

3. The method of forming a tappet which inhollow end portions, placing the core in a flask and casting a head around one end portionv thereof to fill the same at one side of the disc, and then welding a stem to the other end of said core in a manner to leave the other hollow end portion unfilled.

4. The method of forming a tappet which consists in first forming a tubular core with one shouldered and slotted end, inserting a sound ,deadening disc in the core intermediate the ends thereof, placing the core in a flask and casting a head on the shouldered and slotted end thereof 1 to fill the same at one side of the disc, welding a stem to the exposed projecting end of the core in a manner to leave the same unfilled at the opposite side of the disc, and then finish grinding said tappet.

ALBERT S. PLATER. 

